Electrical steel processing without a post cold-rolling intermediate anneal

ABSTRACT

Embodiments of the present invention comprise; annealing steel sheets (e.g., hot rolled steel sheets or thin cast strip steel); cold rolling the sheets in one or more cold rolling steps (e.g., with annealing steps between multiple cold rolling steps); and performing one or more of tension leveling, a rough rolling, or a coating process on the sheets after cold rolling, without an intermediate annealing step between the final cold rolling step and the tension leveling, the rough rolling, or the coating process, or the customer stamping or final customer annealing. In order to achieve the desired properties for the steel sheet, stamping and final annealing is performed by the customer. The new process provides an electrical steel with the similar, same, or better magnetic properties than an electrical steel manufactured using the traditional processing that utilizes an intermediate annealing step after cold rolling and before the stamping and final annealing.

RELATED APPLICATIONS AND PRIORITY CLAIM

This application is a Continuation of co-pending U.S. patent applicationSer. No. 14/797,843 entitled “Electrical Steel Processing Without A PostCold-Rolling Intermediate Anneal” filed on Jul. 13, 2015, which is acontinuation-in-part of, and claims priority to U.S. patent applicationSer. No. 14/334,239 entitled “Electrical Steel Processing Without APost-Cold Rolling Intermediate Anneal,” filed on Jul. 17, 2014, which isa continuation-in-part application, and claims priority to U.S. patentapplication Ser. No. 13/739,184 entitled “Electrical Steel ProcessingWithout A Post-Cold Rolling Intermediate Anneal,” filed on Jan. 11,2013, and which issued into U.S. Pat. No. 10,240,220 on Mar. 26, 2019,which claims priority to Provisional Application No. 61/586,010 filedJan. 12, 2012, and which are all assigned to the assignee hereof andhereby expressly incorporated by reference herein.

BACKGROUND

This invention relates generally to the field of semi-processedelectrical steel sheet manufacturing, and more particularly embodimentsof the invention relate to achieving electrical steel sheet productswith the desired final magnetic properties after they have been annealedat the customer. Semi-processed electrical steel sheets are differentfrom fully processed electrical steel sheets in that the semi-processedelectrical steel sheets manufactured at a steel facility require anadditional customer annealing step performed by the customer before thematerial can be used. Fully processed electrical steel sheets, on theother hand, do not require an additional customer annealing step, andthus, can be used by the customer without further annealing.

BRIEF SUMMARY

The present invention relates to manufacturing semi-processed electricalsteel sheets, formed by systems using methods of manufacturing withoutthe need for annealing after final cold rolling by the electrical steelsheet manufacturer, and before the customer annealing step. The customerannealing step described herein may also be referred to a “finalanneal.”

In various applications, such as electrical motors, lighting ballasts,electrical generators, etc., it may be desirable to use electrical steelproducts that have high saturation, high permeability, and low core lossproperties. Moreover, for electrical motors that operate at highfrequencies, such as for electrical motors in cars or aircraft, theelectrical steel sheets often have thickness less than 0.015 inches(e.g., between 0.011 to 0.013 inches, 0.007 to 0.010 inches, or thelike). For electrical steels, there comes a point in production thatimproving one or more of the high saturation, high permeability, and lowcore loss properties becomes a detriment to one or more of theseproperties, or other properties.

The saturation of the electrical steel is an indication of the highestinduction that the steel can achieve. The permeability of the electricalsteel is the measure of the ability of the steel to support theformation of a magnetic field within itself and is expressed as theratio of the magnetic flux to the field of strength. Electrical steelwith high permeability allows for an increased induction for a givenmagnetic field, and thus, with respect to motor applications, reducesthe need for copper windings, which results in lower copper costs. Thecore loss is the energy wasted in the electrical steel. Low core loss inelectrical steels results in a higher efficiency in the end products,such as motors, generators, ballasts, and the like. Therefore, it may bedesirable in many products to use electrical steels with a high abilityto support a magnetic field and a high efficiency (e.g., highpermeability and low core loss) if it is not detrimental to the cost ofmanufacturing or other desirable steel properties.

Electrical steel is processed with specific compositions, using specificsystems, and using specific methods in order to achieve electricalsteels with the desired saturation, permeability, and core loss, as wellas other properties. Improving one property may come at the detriment ofanother. For example, when increasing the permeability a higher coreloss may result (and vice versa). Consequently, electrical steels areprocessed with specific compositions using specific methods in order tooptimize the desired magnetic properties.

Electrical steel sheets are typically produced by melting scrap steel oriron in an electric furnace (e.g. through compact strip production (CSP)when steel is fed directly into the tunnel furnace, or through anotherprocess in which the steel is cast and reheated at a later point intime), or processing molten steel from iron ore in a blast furnace,described as integrated production. In the integrated process moltensteel is produced in a blast furnace, and in the CSP process the moltensteel is produced using an electric furnace (e.g., electric arc furnace,or other like furnace). A decarburizer (e.g., vacuum degasser, argondecarburizer, etc.) is used to create a vacuum, or change the pressure,in order to utilize oxygen to remove the carbon from the molten metal.Thereafter, the molten steel that is at least substantially free ofoxygen is sent to a ladle metallurgy facility to add the alloyingmaterials to the steel in order to create the desired steel composition.The steel is then poured into ladles and cast into slabs. The steelslabs are hot rolled (e.g., in one or more stages), annealed, coldrolled (e.g., in one or more stages), and intermediately annealed.Thereafter, the steel sheets are sent to the customer for stamping, andcustomer annealing in the case of semi-processed steels. These stepsoccur under various conditions to produce electrical steel sheets withthe desired magnetic properties and physical properties (e.g.,thickness, surface finish, etc.). Other steps may also be performed inorder to achieve the desired magnetic properties.

During the hot rolling step (or between multiple hot rolling steps theelectrical steel sheet may be maintained at a temperature above therecrystallization temperature, which is a temperature at which deformedgrains are replaced by a new set of undeformed grains. Recrystallizationis usually accompanied by a reduction in the strength and hardness of amaterial and a simultaneous increase in the ductility. The hot rollingprocess reduces the thickness of the steel sheet and controls the grainstructure of the electrical steel. After the hot rolling stage(s) thesteel is potentially pickled in a bath (e.g., sulfuric, nitric,hydrochloric, other acids, or combinations of these, etc.) in order toremove scale on the surface of the steel from oxidization. Thereafter,the electrical steel sheet is annealed to change the magnetic propertiesof the steel. During annealing the steel is heated, and thereaftercooled, to coarsen the structure of the steel, and improve cold workingproperties. The electrical steel sheet is then cold rolled afterannealing, which comprises rolling the electrical steel sheet below therecrystallization temperature. Cold rolling may begin at roomtemperatures; however, the temperature of the steel sheet may beelevated at the beginning of the cold rolling process, or otherwise riseduring cold rolling due to the cold rolling process itself. The coldrolling process increases the strength of the steel, improves thesurface finish, and rolls the steel sheet to the desired thickness.

Electrical steel sheets undergoing traditional processing are annealeddirectly after the cold rolling process in order to recrystallize thesteel and achieve the desired permeability and core loss for theelectrical steel in the finished product. The annealing process, bothbefore and after cold rolling, can be done via a continuous annealingprocess or a batch annealing process. In continuous annealing the sheetsof steel are passed through a heating furnace and thereafter cooled in acontinuous sheet. In batch annealing the steel sheets are coiled intorolls and are heated and cooled in batches of coiled rolls.

Temper rolling, in the case of semi-processed steels, may be performedafter annealing in order to improve the surface finish of the electricalsteel sheet, enhance the stamping characteristics, and provide improvedmagnetic properties after the customer has stamped (e.g., punched, orthe like) the electrical steel sheet and performed a final customerannealing step (e.g., heating the stamped part).

After temper rolling, in the case of semi-processed steels producedusing batch annealing, or after continuous annealing of thesemi-processed steels, the electrical steel sheet is sent to thecustomer for further processing. The customer typically stamps theelectrical steel sheet into the required shapes, and thereafter, furtheranneals the stamped shapes in a customer annealing process. The customeranneal is performed by heating the stamped shapes to a specifictemperature and letting them cool in order to maximize the magneticproperties of the stamped electrical steel part. The annealing processafter stamping is performed by the customer because after stamping thestamped shapes have cold-worked edges and the customer annealing processremoves the cold-worked edges, relieves any stress caused by stamping,and maximizes the final magnetic properties of the stamped part.Therefore, in traditional semi-processed electrical steel manufacturingthere are three annealing steps, a pre-anneal before cold rolling, apost cold rolling intermediate anneal, and a final anneal at thecustomer. In still other embodiments of the invention annealing stepsmay also occur between the individual stages of multiple hot rolling orcold rolling passes.

The present invention provides methods and systems that can be used toproduce electrical steels with compositions that provide the same,similar, and/or better magnetic properties (e.g., saturation,permeability, and core loss) than steels that are produced usingtraditional electrical steel processing that utilizes an intermediateannealing step after the final cold rolling pass and before additionalsteel processing, or customer stamping and annealing.

In the present invention, as is the case with traditional electricalsteel processing, scrap steel and/or iron is melted into molten steel ormolten steel is produced from iron ore; the molten steel is sent fordecarburization and for alloy additions; the steel is poured into ladlesand cast into slabs (or continuously cast in some embodiments describedlater); and the slabs are hot rolled, pickled, annealed (e.g., batchannealed or continuously annealed), and cold rolled into sheets.However, unlike traditional electrical steel processing, in the presentinvention, the intermediate annealing step (e.g., the batch annealingstep, or alternatively, the continuous annealing step) after coldrolling is not performed. Instead, in the present invention, after coldrolling a tension leveling step may be performed or a coating may beapplied to the semi-processed electrical steel sheet before it is sentto the customer. At the customer locations, as is the case with thetraditional method for manufacturing semi-processed electrical steels,the customers stamp the electrical steel sheets into the desired shapes,and thereafter, perform a customer annealing step to remove distortionscreated by the stamping and to maximize the magnetic properties of theelectrical steel.

One embodiment of the invention comprises a method of manufacturing anelectrical steel. The method comprises hot rolling steel into a steelsheet in one or more hot rolling passes to a post hot rolling thicknessof less than 0.1 inches; annealing the steel sheet in a first annealafter hot rolling; cold rolling the steel sheet in one or more firstcold rolling passes after the first anneal to a post first cold rollingthickness less than 0.05 inches; annealing the steel sheet in a secondanneal after the one or more first cold rolling passes; cold rolling thesteel sheet in one or more final cold rolling passes after the secondannealing process to a thickness of less than 0.015 inches; and wherebyfinal magnetic properties are achieved in the steel sheet after thesteel sheet is stamped and final annealed without an intermediateannealing process after the one or more final cold rolling passes, andbefore the stamping and the final annealing.

In further accord with an embodiment of the invention, the methodcomprises manufacturing electrical steel with a composition of silicon(Si) in a range of 0.15-3.5% weight; manganese (Mn) in a range of0.005-1% weight; aluminum (Al) less than or equal to 1% weight; carbon(C) less than or equal to 0.04% weight; antimony (Sb) or tin (Sn) lessthan or equal to 0.1% weight; and wherein the remainder comprisesunavoidable impurities and iron.

In another embodiment of the invention, the method comprisesmanufacturing electrical steel with a composition of silicon (Si) is inthe range of 2.8-3.5% weight; manganese (Mn) in a range of 0.2-0.4%weight; and aluminum (Al) in a range of 0.5-0.75% weight.

In still another embodiment of the invention, the method furthercomprises sending the steel sheet to a customer for the stamping and thefinal annealing after the stamping.

In yet another embodiment of the method, the first anneal comprises abatch anneal above 1600 degrees F., and the second anneal comprises abatch anneal above 1500 degrees F.

In further accord with an embodiment of the method, the final thicknessof the steel sheet is 0.011 to 0.013 and the final magnetic propertiescomprise a permeability of greater than 7500 G/Oe and a core loss ofless than 16.0 w/kg when tested at 1.0 T at 400 Hz.

In another embodiment of the method, the final thickness of the steelsheet is 0.007 to 0.010 and the final magnetic properties comprise apermeability greater than 8500 G/Oe and a core loss less than 13.0 w/kgwhen tested at 1.0 T at 400 Hz.

Another embodiment of the invention comprises a method of manufacturingan electrical steel. The method comprises procuring a thin strip caststeel, wherein the thickness of the thin strip cast steel is less thanor equal to 0.05 inches; annealing the thin strip cast steel; coldrolling the steel sheet in one or more cold rolling passes afterannealing to a thickness of less than 0.015 inches; and whereby finalmagnetic properties are achieved in the steel sheet after the steelsheet is stamped and final annealed without an intermediate annealingprocess after the one or more cold rolling passes, and before thestamping and the final annealing.

In further accord with an embodiment of the invention, the methodcomprises manufacturing electrical steel with a composition comprisingsilicon (Si) in a range of 0.15-3.5% weight; manganese (Mn) in a rangeof 0.005-1% weight; aluminum (Al) less than or equal to 1% weight;carbon (C) less than or equal to 0.04% weight; antimony (Sb) or tin (Sn)less than or equal to 0.1% weight; and wherein the remainder comprisesunavoidable impurities and iron.

In another embodiment of the invention, the method comprisesmanufacturing electrical steel with a composition comprising silicon(Si) is in the range of 2.8-3.5% weight; manganese (Mn) in a range of0.2-0.4% weight; and aluminum (Al) in a range of 0.5-0.75% weight.

In still another embodiment, the method further comprises sending thesteel sheet to a customer for the stamping and the final annealing afterthe stamping.

In yet another embodiment of the method, the annealing comprises a batchanneal above 1500 degrees F.

In further accord with an embodiment of the method, the thickness of thesteel sheet is 0.011 to 0.013 and the final magnetic properties comprisea permeability of greater than 7500 G/Oe and a core loss of less than16.0 w/kg when tested at 1.0 T at 400 Hz.

In another embodiment of the method, the thickness of the steel sheet is0.007 to 0.010 and the final magnetic properties comprise a permeabilitygreater than 8500 G/Oe and a core loss less than 13.0 w/kg when testedat 1.0 T @ 400 Hz.

Another embodiment of the invention is an electrical steel, comprisingsilicon (Si) in a range of 0.15-3.5% weight and the remainder comprisesunavoidable impurities and iron. The electrical steel is produced by hotrolling steel in one or more hot rolling passes into a steel sheet to apost hot rolling thickness of less than 0.1 inches; annealing the steelsheet in a first anneal after hot rolling; cold rolling the steel sheetin one or more first cold rolling passes after the first anneal to athickness less than 0.05 inches; annealing the steel sheet in a secondanneal after the one or more first cold rolling passes; cold rolling thesteel sheet in one or more final cold rolling passes after the secondannealing process to a thickness of less than 0.015 inches; and wherebyfinal magnetic properties are achieved in the steel sheet after thesteel sheet is stamped and final annealed without an intermediateannealing process after the one or more final cold rolling passes, andbefore the stamping and the final annealing.

In further accord with an embodiment of the invention, the electricalsteel further comprises manganese (Mn) in a range of 0.005-1% weight;aluminum (Al) less than or equal to 1% weight; carbon (C) less than orequal to 0.04% weight; and antimony (Sb) or tin (Sn) less than or equalto 0.1% weight.

In another embodiment of the invention, the electrical steel comprisessilicon (Si) is in the range of 2.8-3.5% weight; manganese (Mn) in arange of 0.2-0.4% weight; and aluminum (Al) in a range of 0.5-0.75%weight.

In still another embodiment of the invention, the electrical steel isfurther produced by sending the steel sheet to a customer for thestamping and the final annealing after the stamping.

In yet another embodiment of the invention, the first anneal comprises abatch anneal above 1600 degrees F., and the second anneal comprises abatch anneal above 1500 degrees F.

In further accord with an embodiment of the invention, the finalthickness of the steel sheet is 0.011 to 0.013 and the final magneticproperties comprise a permeability of greater than 7500 G/Oe and a coreloss of less than 16.0 w/kg when tested at 400 Hz at 1.0 T.

In another embodiment of the invention, the final thickness of the steelsheet is 0.007 to 0.010 and the final magnetic properties comprise apermeability greater than 8500 G/Oe and a core loss less than 13.0 w/kg.

Another embodiment of the invention is an electrical steel comprisingsilicon (Si) in a range of 0.15-3.5% weight and the remainder of thecomposition of the electrical steel comprises unavoidable impurities andiron. The electrical steel is produced by procuring a thin strip caststeel, wherein the thickness of the thin strip cast steel is less thanor equal to 0.05 inches; annealing the thin strip cast steel; coldrolling the thin strip cast steel in one or more cold rolling passesafter the annealing into a steel sheet with a thickness less than 0.015inches; and whereby final magnetic properties are achieved in the steelsheet after the steel sheet is stamped and final annealed without anintermediate annealing process after the one or more cold rollingpasses, and before the stamping and the final annealing.

In further accord with an embodiment of the invention, the electricalsteel further comprises manganese (Mn) in a range of 0.005-1% weight;aluminum (Al) less than or equal to 1% weight; carbon (C) less than orequal to 0.04% weight; and antimony (Sb) or tin (Sn) less than or equalto 0.1% weight.

In another embodiment of the invention, the composition of theelectrical steel comprises silicon (Si) is in the range of 2.8-3.5%weight; manganese (Mn) in a range of 0.2-0.4% weight; and aluminum (Al)in a range of 0.5-0.75% weight.

In still another embodiment of the invention, wherein the electricalsteel is further produced by sending the steel sheet to a customer forthe stamping and the final annealing after the stamping.

In yet another embodiment of the invention, annealing the thin stripcast steel comprises a batch anneal above 1500 degrees F.

In further accord with an embodiment of the invention, the finalthickness of the steel sheet is 0.011 to 0.013 and the final magneticproperties comprise a permeability of greater than 7500 G/Oe and a coreloss of less than 16.0 w/kg when tested at 1.0 T at 400 Hz.

In another embodiment of the invention, the final thickness of the steelsheet is 0.007 to 0.010 and the final magnetic properties comprise apermeability greater than 8500 G/Oe and a core loss less than 13.0 w/kgwhen tested at 1.0 T at 400 Hz.

To the accomplishment of the foregoing and the related ends, the one ormore embodiments comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth certain illustrative features of the oneor more embodiments. These features are indicative, however, of but afew of the various ways in which the principles of various embodimentsmay be employed, and this description is intended to include all suchembodiments and their equivalents.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Having thus described embodiments of the invention in general terms,reference will now be made to the accompanying drawings, wherein:

FIG. 1A provides a process flow for producing electrical steel, inaccordance with one embodiment of the invention;

FIG. 1B provides a process flow for producing electrical steel, inaccordance with one embodiment of the invention;

FIG. 2 provides an electrical steel processing system environment inaccordance with one embodiment of the invention;

FIG. 3 provides a process flow for producing electrical steels withlower thicknesses using multiple cold rolling steps with intermediateannealing and without annealing after the final cold rolling step; and

FIG. 4 provides a process flow for producing electrical steels withlower thicknesses using thin strip cast steel.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Embodiments of the present invention will now be described more fullyhereinafter with reference to the accompanying drawings, in which some,but not all, embodiments of the invention are shown. Indeed, theinvention may be embodied in many different forms and should not beconstrued as limited to the embodiments set forth herein; rather, theseembodiments are provided so that this disclosure will satisfy applicablelegal requirements. Like numbers refer to like elements throughout.Furthermore, the ranges discussed herein are inclusive ranges.

FIGS. 1A and 1B illustrate flow charts for electrical steel productionprocesses 1, 2 for manufacturing electrical steels with desirablemagnetic properties (e.g., high saturation, high permeability, and lowcore loss) without the need for an annealing step (e.g., continuousannealing or batch annealing) directly after cold rolling (e.g., thefinal cold rolling pass). FIG. 1A illustrates an electrical steelproduction process 1 for manufacturing electrical steel with a tensionleveling and/or coating after cold rolling, while FIG. 1B illustrates anelectrical steel production process 2 for manufacturing electrical steelwith a surface rouging or temper rolling, and tension leveling aftercold rolling. FIG. 2 illustrates an electrical steel processing systemenvironment 200 used in manufacturing the electrical steels inaccordance with the process described in FIGS. 1A and 1B.

As illustrated by block 10 in FIGS. 1A and 1B, scrap steel or iron maybe melted into molten steel in an electric arc furnace 202, asillustrated in FIG. 2. In other embodiments of the invention other typesof furnaces may also be used to produce molten steel from scrap steel.In other embodiments of the invention, molten steel may alternatively beproduced from iron ore. As illustrated by block 20 in FIGS. 1A and 1B,the molten steel may be decarburized by removing all, or substantiallyall, of the oxygen from the molten steel, and thereafter, alloys may beadded to produce the desired composition of the electrical steel. Thedecarburized process step may be performed in a vacuum degasser, argondecarburizer, or other like system, while the alloying additions may bemade in a ladle metallurgy facility, or other like system. Embodimentsof the compositions of various electrical steels will be described indetail below.

As illustrated in block 30 of FIGS. 1A and 1B, the molten steel istransferred to a ladle 204 as illustrated in FIG. 2. Thereafter, asillustrated by block 40 in FIGS. 1A and 1B the ladle 204 supplies atundish 206 with the molten steel and the steel is cast 208 into slabs,as illustrated in FIG. 2. After being cast, the slabs may be sentthrough a tunnel furnace 209 to maintain the desired temperature of theslab, as illustrated by block 45 in FIGS. 1A and 1B, as well as in FIG.2. Upon exiting the tunnel furnace 209 the slabs may be sent directly tothe rolling mill for hot rolling. In other embodiments of the inventionthe steel may be cast 208 into slabs, allowed to cool, and thereafter,at a later time, sent to a re-heater at the rolling mill before beinghot rolled. In still other embodiments of the invention the steel may becontinuously cast into a thin steel sheet and thereafter sent forfurther processing, as discussed later with respect to FIG. 4.

As illustrated by block 50 in FIGS. 1A and 1B, the cast slabs are hotrolled into sheets in one or more hot rolling passes through one or moresets of hot rollers 210. As illustrated by block 55, after hot rolling,the formed sheet may be pickled in order to remove scale (e.g., ironoxide) from the steel sheet. Thereafter, as illustrated by block 60 ofFIGS. 1A and 1B the pickled sheet is coiled and sent for batch annealing212 with one or more other coiled sheets as illustrated in FIG. 2.Alternatively, in some embodiments the sheets may be continuouslyannealed if the manufacturing facility has a continuous annealing line.As illustrated by block 70 in FIGS. 1A and 1B, after batch annealing 212(or continuous annealing in alternative processes) the coiled rolls areuncoiled and cold rolled into thinner sheets in one or more cold rollingpasses through one or more sets of cold rolls 214, as illustrated inFIG. 2.

After cold rolling, unlike traditional electrical steel processing, thecold rolled electrical steel sheets are not processed using furtherannealing. The cold rolling process may produce sheets that have wavyedges or buckling throughout the sheet, such that a customer may not beable to use the sheets for end products. In traditional electrical steelprocessing, annealing the sheets after cold rolling removes the wavyedges and/or buckling from the sheet. However, in the present invention,since there is no annealing step directly after cold rolling (e.g., thefinal cold rolling pass) the sheet may need to undergo a tensionleveling step as illustrated by block 80 in FIG. 1A. During tensionleveling penetrating rollers 216, as illustrated in FIG. 2, transformthe sheet having wavy edges and/or buckling back into a flat sheet(e.g., no wavy edges or buckling), which may be needed in order to allowa customer to properly feed the sheet through a press for the stampingprocess. During tension leveling the sheet is bent over and under (orvice versa) the penetrating rollers 216, as illustrated in FIG. 2. Thepenetrating rolls 216 deform and apply tension to the sheet in order tostretch the sheet to remove the wavy edges and/or buckling.

As illustrated by block 90 in FIG. 1A, after tension leveling a coatingmay be added to the electrical steel sheet. The coating may be added byrunning the sheet through a bath or rolling a coating onto the sheetwhen passing the sheet through a set of coating rolls 218, asillustrated in FIG. 2. The coating (or a rough surface as describedbelow) may be applied to the sheet because when the customer performs anannealing step after the sheet has been stamped, the stamped shapes maystick together such that they may not be separated if the sheet does nothave a coating (or a rough surface). Different types of coatings (orrough surfaces) may be applied to the electrical steel sheets dependingon the needs of the customer.

In some embodiments of the invention, instead of applying a coating, theelectrical steel sheets are produced with a rough surface, asillustrated in FIG. 1B. In some embodiments of the invention, the roughsurface may be applied during the cold rolling process using highroughness rolls, as illustrated by block 75 in FIG. 1B. In otherembodiments of the invention, instead of applying a rough surface to theelectrical steel sheet during cold rolling, the electrical steel sheetmay be passed through a temper rolling process (off-line orcontinuously) after cold rolling and before tension leveling, in orderto achieve the desired rough surface, as also illustrated by block 75 inFIG. 1B. In most applications an electrical steel sheet would not bemanufactured having both a rough surface and a coating, however, theremay be applications where this would be desirable.

Block 100 in FIGS. 1A and 1B illustrates that after the coating isapplied to the electrical steel sheet, the sheet is coiled and sent tothe customer 222, as illustrated in FIG. 2. As illustrated by block 110,the customer stamps the electrical steel sheet into the desired shapes(e.g., the shapes necessary for use in motor cores, ballast lighting,electrical generators, or the like). Thereafter, the customer mayperform a final customer annealing step as illustrated by block 120 inFIGS. 1A and 1B, as is customary in processing semi-processed electricalsteels. During the customer annealing step the stamped shapes are heatedin a heating furnace 224 to remove stresses and to maximize the finalmagnetic properties, as illustrated in FIG. 2.

The desired properties (e.g., saturation, permeability, and core loss)produced during the manufacturing process of the electrical steel aredependent, at least in part, on the grain size of the electrical steel,composition, and processing conditions. The grain sizes, compositions,and process conditions of the electrical steels produced using theprocess of the present invention, for achieving the desired magneticproperties, are described below in more detail in contrast to thetraditional processes used for creating electrical steels and theassociated magnetic properties obtained from the traditional processingmethods. When discussing the properties of the electrical steels herein,the properties are all measured after the final customer annealing step.

In electrical steels processed using traditional manufacturing (e.g.,with an annealing step after cold rolling and before the customerannealing step), the electrical steel sheets typically have a grain sizein the range of 70 to 150 microns. In the present invention the grainsize of electrical steels produced without performing the intermediateannealing step after cold rolling are in the range of 20 to 70 microns,and preferably around 40 microns. The smaller grain size in the presentinvention helps to create high permeability in the electrical steelbecause it is easier to magnetize smaller domain structures. Magneticdomain structures are regions within the grains that have the samemagnetic orientation. The boundary (e.g., walls) of the domains movewhen an applied magnetic field changes size or direction. The smallerthe grain size the smaller the domain structure, and thus, the easier itis to support the magnetic field. Therefore, the permeability of themagnetic structure is increased.

Alternatively, the smaller grain size may have a negative effect on thecore loss, that is, the smaller the grain size the greater thehysteresis portion of core loss realized in the electrical steel. At thelower levels of grain size, such as around 20 microns, the increasedcore loss may not be ideal for some electrical steels depending on theproducts in which they are used. Therefore, reducing the grain size inthe new process to 20 to 70 microns from the 70-150 microns seen intraditional processing, may greatly improve permeability with only aminor increase in core loss. The optimal grain size for electrical steelsheets in some products, such as motors, may be around 40 (e.g., 30 to50) microns in order to achieve the desired permeability and corelosses.

The grain texture may also play a role in improving the permeability andreducing the core loss. The grain texture is described as theorientation of the grains. Developing non-oriented electrical steelswith improved grain texture (e.g., more oriented grains in variousdirections) may increase the permeability and/or reduce the core loss.

The grain size, and thus, the magnetic properties of the electricalsteels can be controlled, in part, by the composition of the electricalsteels. The compositions of the electrical steels used in the presentinvention may have the ranges disclosed in Table 1. The ranges disclosedin Table 1 illustrate examples of the percent weight of Silicon,Aluminum, Manganese, Carbon, and/or Antimony that provide the desiredelectrical steel sheets with high permeability and low core loss usingthe process of the present invention that excludes the intermediateannealing step after cold rolling and before the customer annealingstep. In other embodiments of the invention smaller ranges of theseelements may be more acceptable in producing the desired highpermeability and low core loss. Furthermore, in some embodiments of theinvention Tin (Sn) may replace Antimony (Sb) or be used in combinationwith Antimony, to achieve the desired magnetic properties. Thecomposition of Sn may be less than or equal to 0.1% weight. In otherembodiments of the invention various combinations of the elements inTable 1, as well as other elements (e.g., Sn, etc.), may be used toproduce electrical steels with the desired magnetic properties withoutthe need for the intermediate annealing step directly after cold rollingand before customer annealing. For example, in some embodiments only thesilicon, aluminum, and manganese alloys are controlled and/or added tothe molten steel. In still other embodiments of the invention only thesilicon is controlled and/or added, and thus, the other elements are notcontrolled and/or added outside of any unavoidable impurities. In theembodiments presented herein the compositions may have one or more otherelements that are present as unavoidable impurities with the remainderof the compositions comprising iron. In still other embodiments of theinvention the composition of electrical steels may include rangesbetween, overlapping, or outside of two or more specific recitations ofelement percentages described herein (e.g., 0.15%, 0.4%, 0.6%, 1.05%,1.35%, 2.2%, 2.24%, 2.6%, 3.0%, 3.5%, or the like of Si).

TABLE 1 Range of Elements for Desired Electrical Steel Permeability andCore Loss Properties Element Composition (by weight percent) Silicon(Si) 0.15-3.5% Aluminum (Al) <=1% (or 0.15-1%) Manganese (Mn) 0.005-1%  Carbon (C) <=0.04% (or <=0.02%) Antimony (Sb) <=0.1%

The amount of silicon used in the electrical steel controls many aspectsof the magnetic properties of the electrical steel. Silicon may be addedto electrical steels to raise the resistivity of the material andconcurrently reduce the eddy current loss component of the core loss.Alternatively, the lower the silicon level the higher the permeabilityand the higher the saturation. Thus, there is also a benefit to reducingthe silicon in order to increase the permeability and allow theelectrical steel to more easily support a magnetic field (e.g., at highmagnitude inductions). Furthermore, the purer the electrical steel thehigher the saturation level, and thus, the more magnetic induction canoccur.

In the present invention the removal of the annealing step after coldrolling results in a minor degradation in core loss (e.g., core lossincreases a small amount), but the permeability is much higher thanelectrical steels processed using traditional methods (e.g., as testedabove 1.3 Tesla, 1.4 Tesla, 1.5 Tesla, or more than 1.5 Tesla, oroutside of these Tesla ranges for example at 1.0 Tesla for thinnersteels used in high frequency applications). The small degradation incore loss can be recovered by increasing the level of silicon, such thatthe final product produced using the process in the present inventioncan have the same or better core loss and much better permeability thanelectrical steels produced using the traditional processes thatincorporate an intermediate annealing step after cold rolling and beforestamping and annealing at the customer.

The processing conditions may also have an impact on the magneticproperties of the electrical steel. The ranges of conditions forprocessing the electrical steel in the present invention may vary basedon the composition of the steels and/or magnetic properties desired.Examples of the ranges of processing temperatures are provided in Table2A.

TABLE 2A Conditions for Producing the Electrical Steels with the DesiredPermeability and Core Loss Process Step Temperature Range Tunnel FurnaceExit 1800 to 2300 Degrees F. Temperature Hot Rolling Finish 1450 to 1800Degrees F. Temperature Coiling Temperature 900 to 1500 Degrees F. BatchAnneal Soak Temp 1000 to 1900 Degrees F. (or 2100 Deg F.) (in lieu ofContinuous Anneal) Continuous Anneal Temp 1400 to 2000 Degrees F. (or2100 Deg F.) (in lieu of Batch Anneal) Cold Rolling Temperature Ambient,or greater (May need > 100 F. for Si > 2.0%) Customer Anneal 1400 to1675 F., or greater, for 45 min. to 1 hour

Table 2B illustrates temperature ranges, which are narrower than theranges described in Table 2A, in accordance with other embodiments ofthe processing conditions for manufacturing the electrical steels withthe magnetic properties described herein. In still other embodiments ofthe invention the ranges of conditions for processing the electricalsteels in the present invention may be a combination of the rangesdescribed in Tables 2A and 2B, within the ranges described in Tables 2Aand 2B, overlapping the ranges described in Tables 2A and 2B, or outsideof the ranges described in Tables 2A and 2B.

TABLE 2B Conditions for Producing the Electrical Steels with the DesiredPermeability and Core Loss Process Step Temperature Range Tunnel FurnaceExit Temperature 1800 to 2150 Degrees F. Hot Rolling Finish Temperature1500 to 1700 Degrees F. Coiling Temperature 950 to 1450 Degrees F. BatchAnneal Soak Temp 1000 to 1550 Degrees F. (in lieu of Continuous Anneal)(or to 1900 Deg F.) Continuous Anneal Temp 1550 to 1900 Degrees F. (inlieu of Batch Anneal) Cold Rolling Temperature Ambient, or greater (Mayneed > 100 F. for Si > 2.0%) Customer Anneal 1450 to 1550 F., orgreater, for 45 min. to 1 hour

For the higher levels of silicon content (e.g., greater than or equal to2.2%, 2.6%, and/or 3.0%) the pre-annealing step between hot rolling andcold rolling may have to occur at the higher end of the listedtemperature ranges. For example, the annealing temperature may berequired to be at or above 1450, 1500, 1550, 1600, 1650, 1700, 1750,1800, 1850, 1900, 1950, 2000, 2050, or 2100 degrees F. The annealingtemperature range may be within, overlapping, or outside of any of theseannealing temperatures. These temperatures for annealing may be neededto achieve the desired grain sizes in the steel. These annealingtemperatures may also be used at the lower silicon levels if needed.

The core loss is also a function of the thickness of the electricalsteel sheet. After hot rolling, the electrical steel sheet may have athickness between 0.060″ to 0.120.″ After cold rolling, the electricalsteel sheet may have a thickness between 0.005″ to 0.035.″ The thinnerthe final thickness of the steel sheet the lower the core loss and thebetter the efficiency of the electrical steel (e.g., with otherparameters being equal). In other embodiments of the invention, thethickness of the electrical steel sheet after hot rolling and coldrolling may be within, overlap, or be outside of these ranges.

The following examples illustrate the improved magnetic properties thatmay be achieved using the present invention. As a first example,electrical steel of the composition illustrated in Table 3 was processedusing the traditional process versus the process of the presentinvention according to the processing temperatures illustrated in Table4 (e.g., there may be other process steps in addition to the stepsillustrated in Table 4, for example in the traditional process atempering rolling step may occur after batch annealing). The resultingelectrical properties of the electrical steels are contrasted in Table5. As disclosed in Table 3, the electrical steels tested in this examplehad a silicon composition of 1.35% weight.

TABLE 3 Composition of Electrical Steel Tested - 1.35% Si Sample ElementComposition (by weight percent) Silicon 1.35% Aluminum 0.33% Manganese0.65% Carbon 0.005%  Antimony 0.065% 

TABLE 4 Conditions for Producing The Electrical Steel - 1.35% Si SampleProduct Process Step Temperature Thickness Tunnel Furnace ExitTemperature 2000 Degrees F. 2.0″ Hot Rolling Finish Temperature 1550Degrees F. 0.080″ Coiling Temperature 1000 Degrees F. 0.080″ BatchAnneal Soak Temperature 1530 Degrees F. 0.080″ Cold Rolling TemperatureAmbient 0.0197″ Batch Anneal Soak Temperature 1240 Degrees F. 0.0197″(For Traditional Process ONLY) Customer Anneal 1450 Degrees F. for0.0197″ one hour at 55 Degrees F. Dewpoint

TABLE 5 Electrical Steel Properties - 1.35% Si Sample New ProcessTraditional Process Properties (1 Sample in 4 areas) (10 Samples invarious areas) Core Loss  1.99-2.05 W/lb  1.81-1.93 W/lb Permeability3180-3429 Gauss/Oersted 1716-1944 Gauss/Oersted

Table 5 provides the ranges of core loss and permeability for electricalsteels produced using the process of the present invention versuselectrical steels produced using the traditional process that utilizesan annealing step after cold rolling and before customer annealing. Allof the electrical steels tested in Table 5 had the same compositions, asillustrated in Table 3, were produced using the conditions illustratedin Table 4 (e.g., new process or traditional process), and were testedat the universal standard of 1.5 Tesla @ 60 Hz. Table 5 illustrates thatthe core loss using the new process only slightly increased to 1.99-2.05W/lb from 1.81-1.93 W/lb using the traditional process, while thepermeability using the new process greatly increased to a range of3180-3429 G/Oe from 1716-1944 G/Oe using the traditional process. Asillustrated by Table 5, the electrical steels produced using the newprocess have magnetic properties with a slightly increased core loss andmuch better permeability than the electrical steels produced using thetraditional processing methods.

By increasing the silicon level in the composition and using the newprocessing method of the present invention, electrical steels may beproduced that have the same or lower core loss and higher permeabilitywhile removing the need for an intermediate annealing step directlyafter cold rolling, as explained in further detail below with respect toTables 6, 7, and 8.

As a second example, Table 8 provides the ranges of core loss andpermeability for electrical steels produced using the process of thepresent invention versus electrical steels produced using thetraditional process that utilizes an intermediate annealing step aftercold rolling. The electrical steels tested had the same compositions, asillustrated in Table 6, were produced using the conditions illustratedin Table 7 (with the exception of the customer annealing temperature),and were tested at the universal standard of 1.5 Tesla @ 60 Hz. Table 8illustrates that the core loss using the new process only slightlyincreased to 1.58-1.63 W/lb from 1.50-1.54 W/lb using the traditionalprocess, while the permeability using the new process greatly increasedto a range of 2379-2655 G/Oe from 1259-1318 Ga/Oe using the traditionalprocess. As illustrated by Table 8, the electrical steels produced usingthe new process have magnetic properties with a slightly increased coreloss and much better permeability than the electrical steels producedusing the traditional processing methods as explained below.

TABLE 6 Composition of Electrical Steel Tested - 2.24% Si Sample ElementComposition (by weight percent) Silicon 2.24% Aluminum 0.41% Manganese0.35% Carbon 0.005%  Antimony 0.066% 

TABLE 7 Conditions for Producing The Electrical Steel - 2.24% Si SampleProcess Step Temperature Product Thickness Tunnel Furnace Exit 2000Degrees F. 2.0″ Temperature Hot Rolling Finish Temperature 1550 DegreesF. 0.080″ Coiling Temperature 1000 Degrees F. 0.080″ Batch Anneal SoakTemperature 1530 Degrees F. 0.080″ Cold Rolling Temperature Ambient Newprocess = 0.0193-0.0197″ Traditional Process ≈ 0.0187″ Batch Anneal SoakTemperature 1240 Degrees F. New process = 0.0193-0.0197″ (ForTraditional Process Traditional Process ≈ 0.0187″ ONLY) Customer Anneal1550 Degrees F. for the new process New process = 0.0193-0.0197″ (1450Degrees for the traditional Traditional Process ≈ 0.0187″ process) forone hour at 55 Degrees F. Dewpoint

TABLE 8 Electrical Steel Properties New Process Traditional ProcessProperties (1 Sample at head and tail) (1 Sample at head and tail) CoreLoss  1.58-1.63 W/lb  1.50-1.54 W/lb Permeability 2379-2655Gauss/Oersted 1259-1318 Gauss/Oersted

As disclosed in Table 6, the electrical steel produced had a siliconcomposition of 2.24% weight, which was an increase of 0.89% weight overthe composition tested in Table 3. Furthermore, the composition ofAluminum in the steel increased from 0.33% weight to 0.41% weight, thecomposition of Manganese decreased from 0.65% weight to 0.35% weight,while the composition of Carbon and Antimony did not change or had onlyminor differences between the steel tested in Table 3 and the steeltested in Table 6.

Table 7 illustrates the process conditions for producing the electricalsteel with the 2.24% Silicon weight composition. As illustrated in Table7, the process conditions are the same as previously described withrespect to Table 4 except for the increase in the customer annealingtemperature from 1450 degrees F. using the traditional process to 1550degrees F. for the new process without the intermediate annealing stepafter cold rolling. As explained in further detail later, the increasein the customer annealing temperature may also play a role in improvingthe magnetic properties of the electrical steel (e.g., reducing the coreloss and/or improving the permeability). There is also a minordifference in the samples tested for the 2.24% Silicon steel using thenew process and the sample tested for the 2.24% Silicon steel using thetraditional process, in that the steel tested in the new process isslightly thicker than the steel tested using the traditional process.The small differences in thickness may have a small effect on themagnetic properties of the electrical steel. However, small changes inthicknesses may also occur over the span of a steel sheet itself, andthus, may only negligibly affect the magnetic properties of the steel.In addition, small differences in core loss, permeability, or othermagnetic or material properties may be a function of the hot rollingparameters. For example, the head of the coil and the tail of the coilmay experience different hot rolling parameters (e.g., small differencesin temperature, pressure, or the like). For example, as illustrated inTable 8 the thickness differences between the head and tail ordifferences in the hot rolling parameters may affect the core loss andpermeability, such that core loss and permeability at the head may be1.58 w/lb and 2379, while the core loss and permeability at the tail maybe 1.63 w/lb and 2655.

As was the case with the first example, illustrated in Tables 3-5, inthe second example, as illustrated in Tables 6-8, the electrical steelsproduced using the new process have magnetic properties with a slightlyincreased core loss and much better permeability than the electricalsteels produced using the traditional processing methods.

As described throughout the specification, in order to improve themagnetic properties of the steel over the traditional processingmethods, steel may be produced using the new process without anintermediate step of annealing after cold rolling and before theoptional steps of tension leveling and coating or temper rolling, aswell as before the customer annealing step.

As illustrated by the examples set forth herein, by removing theintermediate annealing step after cold rolling (e.g., a final coldrolling pass) and increasing the amount of silicon in the steel, thepresent invention has improved upon the magnetic properties found in theelectrical steels processed in the traditional way using an intermediateannealing step after cold rolling and before the customer annealingstep. This point is illustrated in a comparison of Table 5 and Table 8,which illustrates that by using the new processing method and increasingthe Silicon composition from 1.35% weight to 2.24% weight, improvedmagnetic properties can be achieved that result in both improved coreloss (illustrated as a reduction in core loss from the range of1.81-1.93 W/lb to the range of 1.58-1.63 W/lb) and improved permeability(illustrated as an increase in permeability from the range of 1716-1944Gauss/Oersted to the range of 2379-2655 Gauss/Oersted).

Table 9 further illustrates the changes in core loss and permeability asthe Silicon content of a steel increases and as the customer annealingtemperature increases. As explained herein, core loss generally improves(illustrated as a decrease in core loss) as Silicon content increases,except when reaching the higher end the in the Silicon range(0.15-3.5%). As illustrated in Table 9, when the Silicon content reacheslevels of approximately 2.6% to 3.5% the core loss may generally degrade(illustrated as an increase in core loss). The effects of the degradedcore loss at the elevated Silicon levels may be mitigated or reversed byincreasing the customer annealing temperature. As illustrated in Table9, as the customer annealing temperature is raised from 1450 degrees F.to 1550 degrees F. (or higher) the core loss improves (illustrated as adecrease in core loss) across the ranges of Silicon from 2.2%-3.0%, suchthat the core loss only has slight variations with the changing Siliconlevels at the higher annealing temperatures. Furthermore, core loss maybe improved across the entire range of Silicon content when the customerannealing temperature increases, however, this benefit may be morenoticeable as the level of Silicon increases. In some embodiments of theinvention the annealing temperature may be increased up to 1600 degreesF. or 1700 degrees F., or more as described throughout thisspecification, in order to improve the core loss (illustrated as adecrease in value of the core loss). The carbon content of the steelsmay also play a role in the magnetic properties. The 2.6% and 3.0%Silicon steels illustrated in Table 9 had slightly higher carbon levelsthan the 2.2% Silicon steel, and as such the core loss measurements wererelatively the same or slightly increased over the 2.2% Silicon steelcore loss. If the carbon content in the 2.6% and the 3.0% Silicon steelswere the same as the 2.2% Silicon steel the core loss in the 2.6%Silicon steel may have been reduced when compared to the 2.2% Siliconsteel, and the core loss in the 3.0% Silicon steel may have been reducedwhen compared to the 2.2% Silicon steel and the 2.6% Silicon steel.

TABLE 9 Si Content vs. Properties vs. Intermediate Batch AnnealingTemperatures For 0.0198″ Thickness 1450 F. Customer Annealing 1550 F.Customer Annealing Si Content Core Loss Permeability Core LossPermeability 2.2%   1.79 W/lb    2436 G/Oe 1.61-1.67 W/lb 2328-2645 G/Oe2.6% 1.69-1.71 W/lb 2215-2308 G/Oe 1.62-1.63 W/lb 2175-2191 G/Oe 3.0%1.71-1.81 W/lb 1665-1733 G/Oe 1.64-1.70 W/lb 1592-1745 G/Oe

The improvement to the core loss by increasing the customer annealingtemperature is also present at various sheet thicknesses. Table 10illustrates the changes in magnetic properties of a 2.2% Silicon steelhaving a thickness of 0.0147″ between customer annealing processestaking place at 1470 degrees F. and at 1550 degrees F. As illustrated inTable 10, as the customer annealing temperature increases the core lossdecreases. Moreover, additional improvements in core loss orpermeability may be realized by further increasing the customerannealing temperature to greater than 1600, 1650, 1700, 1750, or thelike degrees F., or more as described throughout this specification.Furthermore, this improvement may occur at other levels of Siliconcontent (e.g., Silicon from 0.15 to 3.5%). Moreover, a comparison of the2.2% Silicon electrical steel of Table 9 and the 2.2% Silicon electricalsteel of Table 10 illustrates that as the thickness of the electricalsteel sheet is reduced the core loss is improved (e.g., it decreases),with a small degradation in the permeability (e.g., it decreases).

TABLE 10 Properties vs. Customer Annealing Temperatures ForApproximately 0.0147″ Thickness Si 1470 F. Customer 1550 F. CustomerCon- Annealing Annealing tent Core Loss Permeability Core LossPermeability 2.2% 1.525 W/lb 2149 G/Oe 1.380-1.396 W/lb 2312-2343 G/Oe

In still other embodiments of the invention improvements in core lossand permeability may be achieved as the Silicon content of a steelincreases by increasing the annealing temperature between hot-rollingand cold-rolling. As explained herein, core loss generally improves(illustrated as decrease in core loss) as Silicon content increases,except potentially when reaching the higher end of the Silicon range(0.15-3.5%), for example, with a Silicon content of approximately 2.6%to 3.5%, the core loss may generally degrade (illustrated as an increasein core loss). The effects of the degraded core loss at the elevatedSilicon levels may be mitigated or reversed by increasing thetemperature of the annealing process between the hot-rolling andcold-rolling steps. For example, increasing the annealing temperature togreater than 1600, 1650, 1700, 1750 degrees F., or more, as describedthroughout this specification, improves the core loss. In someembodiments, batch annealing at our around 1700 degrees F. may be themost cost effective for a batch annealing process. As temperatures forthe batch annealing process increase over 1700, 1750, 1800, or the like,the furnaces in which the batch annealing occurs may require moreexpensive materials in order to protect the furnace from the hightemperatures. As such, the most cost effective temperature for batchannealing that produces the desired results herein may be 1600, 1650,1700, 1725, 1750, 1775, or 1800 degrees F., or any temperature or rangeof temperatures that fall within or overlap these temperature values.

By controlling the processing times, processing temperatures, and steelcompositions within the new process, electrical steels with the desiredmagnetic properties required by the customers are developed without theneed for an intermediate annealing step after cold rolling and beforethe customer stamping and customer annealing process. Moreover, theseimprovements may also be achieved using a batch annealing processinstead of a continuous annealing line, which would require a largecapital investment (e.g., 150 million US dollars or more). Batchannealing furnaces are much less expensive than installing a continuousannealing line. In some embodiments of the invention it is also notedthat adding a coating, as described herein, may further improve thepermeability of the electrical steel.

Another difference between electrical steels produced using traditionalprocessing methods and electrical steels produced without anintermediate annealing step directly after cold rolling is that in thepresent invention the electrical steels are harder. For example, in thepresent invention the Rb hardness, which is a standardize hardnessmeasurement, of the electrical steel may generally be in the range of 90to 100 (or in some embodiments outside of this range), or morespecifically in the high 90's. Alternatively, the hardness of theelectrical steels manufactured using the traditional method may be 50 to80 Rb.

Based on a number of factors, including but not limited to the siliconcontent of the steel, the thickness of the steel sheet, the annealingtemperatures, and the process of performing an annealing step betweenhot rolling and before cold rolling and forgoing an annealing step afterthe last cold rolling pass before the sheet is sent to the customer forfurther processing, the core losses and permeability may fall within anumber of different ranges. In some embodiments of the invention thecore loss may be below 3.5, 3.25, 3, 2.75, 2.50, 2.25, 2, 1.75, 1.5,1.25, or 1 W/lb, may be within, overlapping, or outside of any rangesbetween these core loss values or other core loss values notspecifically recited. In addition to these core loss values, thepermeability may be greater than 1000, 1100, 1200, 1250, 1300, 1350,1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950,2000, 2050, 2100, 2150, 2200, 2250, 2300, 2350, 2400, 2450, 2500, 2550,2600, 2650, 2700, 2750, 2800, 2850, 2900, 2950, 3000, 3050, 3100, 3150,3200, 3250, 3300, 3350, 3400, 3450, or 3500 G/Oe, may be within,overlapping, or outside of any ranges between these permeability valuesor other permeability values not specifically recited.

As illustrated by some of the testing results, a silicon content of upto 3.5% (or in other embodiments up to 3.0%) may result in permeabilityvalues that may exceed 1400, 1450, 1500, 1550, or 1600 G/Oe, or anyother type of permeability values illustrated herein (e.g., when testedat 1.5 T and 60 Hz). At these levels of silicon (e.g., 3.5%, 3%, or thelike) the core loss may be less than 2, 1.75, 1.50, 1.25, 1 W/lb orother like core loss values. In other embodiments of the invention, thepermeability values and the core less values may be within, outside of,or overlap these values or other values discussed herein. Generally, asthe silicon level drops the core loss and the permeability will bothincrease (e.g., the core loss is degraded and the permeabilityimproves). This statement is applicable when all other factors remainunchanged because other factors such as the thickness of the steelsheets and the temperatures of the annealing steps may impact the coreloss and permeability values. At the lower levels of silicon, forexample 0.6%, the core loss may be less than 4.5, 4.0, 3.5, 3.0, 2.6,2.5 W/lb, and the permeability may be greater than 2000, 2050, 2100,2150, and 2200 G/Oe (or greater than other levels discussed herein)(e.g., when tested at 1.5 T and 60 Hz). In other embodiments of theinvention the core loss and permeability values may fall within, belocated outside of, or overlap any of these values.

Table 11 below illustrates additional testing that has occurred forvarious types of steel with various types of silicon formed from theprocesses of the present invention discussed herein. As illustrated inTable 11, the concepts that were previously discussed herein are furthersupported by the additional testing of steel sheets processed without apost cold-rolled anneal after the last cold-rolling step and before thesteel is shipped to a customer for stamping and final annealing. For the2.2% silicon content steel, Table 11 illustrates generally that as thecustomer annealing temperature is increased the core loss valuedecreases (e.g., is improved). Moreover, with respect to steel with the2.6% silicon, Table 11 illustrates generally that as the customerannealing temperature is increased the core loss value decreases (e.g.,is improved). Finally, with respect to the 3% silicon content steel,Table 11 also illustrates generally that as the customer annealingtemperature is increased the core loss value decreases (e.g., isimproved). Table 11 further indicates that as the customer annealingtemperature changes the permeability fluctuates. The changes inpermeability may be based not only on the changes in Silicon content,but also on the thickness, location on the steel sheet at which thepermeability is tested, composition of the steel (e.g., carbon content,or other element), and/or other factors.

TABLE 11 Si Content vs. Thickness vs. Customer Annealing Temperature vs.Magnetic Properties Customer Annealing Si Content Thickness TemperatureCore Loss Permeability 2.2% 0.0198″ 1450 Deg F. 1.787 W/lb 2436 G/Oe2.2% 0.0184″ 1550 Deg F.  1.67 W/lb 2449 G/Oe 2.2% 0.0197″ 1550 Deg F.1.617 W/lb 2328 G/Oe 2.2% 0.0197″ 1550 Deg F. 1.667 W/lb 2645 G/Oe 2.2%0.01975″ 1550 Deg F.  1.72 W/lb 2232 G/Oe 2.6% 0.0196″ 1450 Deg F. 1.694W/lb 2308 G/Oe 2.6% 0.0205″ 1450 Deg F. 1.617 W/lb 2175 G/Oe 2.6%0.0199″ 1550 Deg F. 1.628 W/lb 2191 G/Oe 2.6% 0.0206″ 1550 Deg F. 1.617W/lb 2175 G/Oe   3% 0.0206″ 1450 Deg F. 1.711 W/lb 1665 G/Oe   3%0.0206″ 1450 Deg F. 1.805 W/lb 1733 G/Oe   3% 0.0206″ 1550 Deg F. 1.642W/lb 1592 G/Oe   3% 0.0206″ 1550 Deg F. 1.696 W/lb 1745 G/Oe

In other embodiments of the invention additional process steps may beadded, or processing steps may be changed, in order to achieve thedesired magnetic properties (e.g., core loss, permeability, or the like)of a steel sheet manufactured by performing an annealing step betweenhot rolling and cold-rolling without an annealing step after a finalcold-rolling pass and before customer stamping and annealing. Asdescribed above, one embodiment of the present invention may comprisehot rolling, pickling, annealing (e.g., batch annealing or continuousannealing), cold rolling, and tension leveling and coating, or surfaceroughing or temper rolling and tension leveling. As such, there is noannealing step after the last cold rolling step and before the tensionleveling and coating, or roughing or temper rolling and tensionleveling, as well as before shipment to the customer for stamping andfinal annealing. In alternate embodiments of the invention describedabove, the cold rolling process may occur in multiple steps of two ormore cold rolling passes through one or more cold rolling stands, whichmay further include annealing steps between the two or more cold rollingpasses. Regardless of the number of cold rolling passes and annealingsteps between the cold rolling passes, in the present invention there isno intermediate annealing step after the final cold rolling pass andbefore the tension leveling and coating, or roughing or temper rollingand tension leveling, as well as before the customer stamping andannealing.

As discussed above, the thicknesses of the steel sheets after coldrolling are described herein as ranging between 0.005″ to 0.035.″ At thelower end of the range of the thickness of the steel sheets, such asfrom approximately 0.005 inches to 0.01, 0.0125, 0.015, 0.018, 0.02inches (or other ranges that fall within, outside of, or overlap theseranges), multiple cold rolling passes may be needed with one or moreannealing steps between the multiple cold rolling passes in order toachieve the desired mechanical properties at the lower end of thethickness ranges for the steel sheets. In other embodiments, multiplecold rolling steps may also be used up to thicknesses of 0.025″, 0.031″,and/or 0.035.″ In addition to the multiple cold rolling steps, in someembodiments the amount of silicon in the composition of the steel mayalso play a role in the thickness of the steel sheets, or otherwisedetermine how many cold rolling steps are needed. For example, dependingon the equipment used during the rolling processes, the higher siliconcontent the harder it may be to achieve the thinner steel sheets. Injust one example, when using steel with a silicon content that isapproximately 3% (e.g., greater than 2.9 percent) it may be difficult toroll the steel strips to lower than 0.014, 0.013, 0.012, 0.011, or thelike inches with one cold-rolling pass. As such, in some embodimentsmultiple cold-rolling steps may be needed to achieve the recitedthickness ranges. In other embodiments, regardless of the number of coldrolling steps, thicknesses lower than the recited values, or other likevalues not specifically listed, may not be reached at all.

Table 12 illustrates a comparison of steels that are on the lower end ofthe thickness range and have the same compositions (e.g., 2.2% silicon),but are processed using different types of routings. The first routingprocess in Table 12 includes a batch anneal before cold rolling and abatch anneal at 1450 Deg F. after the final cold rolling step (e.g.,single cold rolling step) before shipping to the customer for stampingand final annealing (e.g., defined as a motor lam semi-processed steel).The second routing process in Table 12 includes a batch anneal beforecold rolling and a batch anneal at 1550 Deg F. after cold rolling step(e.g., single cold rolling step) before shipping to the customer forstamping and final annealing (e.g., also defined as a motor lamsemi-processed steel). The final routing process illustrated in Table 12does not include an annealing step after cold rolling and beforecustomer stamping and customer final annealing (e.g., the new process ofthe present invention). As illustrated in Table 12 the steel of thepresent invention (e.g., the third routing) has approximately the samecore loss (1.595 vs. 1.59 W/lb) as the steel produced from thetraditional process that is customer annealed at 1550 Deg F., and has abetter permeability (2240 vs. 1904 G/Oe). The present invention also hasslightly worse core loss (1.595 vs. 1.265 W/lb) than steel produced fromthe traditional process that is customer annealed at 1450 Deg F., and amuch better permeability (2240 vs. 1179 G/Oe). As such, in order toimprove the core loss with only slightly losing some permeability, thesilicon content of the steel in the present invention is increased. Theincrease in the silicon content allows the steel to achieve the same orbetter magnetic properties of the semi-processed motor lam steel withoutthe annealing step after the last cold-rolling process.

TABLE 12 Routing Process vs. Thickness vs. Customer AnnealingTemperature vs. Magnetic Properties Si Customer Content Routing ProcessThickness Anneal Temp Core Loss Perm. 2.2% 1) Hot Rolling, BatchAnnealing, Cold Rolling, 0.0137″ 1450 Deg F. 1.265 W/lb 1179 G/Oe BatchAnnealing, Temper Rolling, Customer Stamping and Annealing 2.2% 2) HotRolling, Batch Annealing, Cold Rolling, 0.0137″ 1550 Deg F.  1.59 W/lb1904 G/Oe Batch Annealing, Customer Stamping and Annealing 2.2% 3)Present Invention: Hot Rolling, Batch 0.0139″ 1550 Deg F. 1.595 W/lb2240 G/Oe Annealing, Cold Rolling, Customer Stamping and Annealing

As previously discussed, it may be difficult to achieve the thicknessesillustrated in Table 12 for the higher levels of silicon (e.g., greaterthan 2.6%, such as 3%, or the like). In some embodiments of the presentinvention, as illustrated in FIG. 3, the steelmaking process may includethe same steps as illustrated in FIGS. 1A and 1B with an additional coldrolling step and/or an additional annealing step between the coldrolling steps. As such, after melting, alloying, transferring to aladle, casting into slabs, and heating the slabs or direct hot-rollingfrom casting (as illustrated in blocks 10-45), the slabs are hot rolledfor one or more passes into sheets as illustrated by block 50 of FIG. 3.As illustrated by block 55, the hot-rolled sheets are pickled. Anannealing step (e.g., batch annealing or continuous annealing) followsthe hot rolling step and the pickling step, as illustrated by block 60.This annealing step, as previously discussed, may occur at a temperaturewithin a range of 1000 to 1900 or 2100 Degrees F., or fall within, beoutside of, or overlap these ranges. After annealing, the sheet ispassed through a first cold rolling step (e.g., in one or more passes)as illustrated by block 71, in order to reduce the thickness of thesheet to a range of less than approximately 0.100,″ 0.090,″ 0.080″ to0.060″, 0.050″, 0.040″ or 0.020″ (or other ranges that fall within, areoutside of, or overlap these ranges). As illustrated by block 72, anannealing step (e.g., batch annealing or continuous annealing) after thefirst cold-rolling pass may be performed in order to recover theductility of the sheet, to reduce the dislocation density of the sheetfor reducing residual stresses in the sheet, and to help achieve thedesired electrical steel properties. The annealing step after the firstcold rolling step may be performed at a temperature of 1000 to 1900 or2100 Deg F., or fall within, be outside of, or overlap these ranges (asdescribed throughout). After the intermediate annealing step after thefirst cold-rolling step, a subsequent (e.g., final, last, or the like)cold rolling step (e.g., in one or more passes) is performed to furtherreduce the thickness of the sheet to the desired thickness range of0.005″ to 0.018″ or 0.02″ (or other ranges that fall within, outside of,or overlap these ranges such as up to 0.025″, 0.031″, or 0.035″), asillustrated in block 73 of FIG. 3. In other embodiments of the inventionthere may be additional cold rolling passes (e.g., second, third,fourth, fifth, or more), each with intermediate annealing steps, beforethe final cold rolling step. However, in some embodiments there may onlybe two cold rolling steps (e.g., each with one or more passes) with asingle annealing step between the two cold rolling steps. After thefinal (e.g., last) cold rolling step, further annealing of the steelsheet is not performed before the optional steps of roughing or temperrolling, tension leveling, and/or coating, as illustrated by blocks 75,80, 90 of FIG. 3. Moreover, there is no annealing step after coldrolling and before the sheet is shipped to the customer for stamping andcustomer annealing, as illustrated by blocks 100, 110, and 120. As such,while there are one or more intermediate annealing steps between themultiple cold rolling passes there is no annealing step after the finalcold rolling pass and before the semi-processed steel is sent to thecustomer for stamping and final annealing. Table 13 illustrates oneembodiment of the process of the present invention using two coldrolling steps.

TABLE 13 Conditions for Producing the Electrical Steels with the DesiredPermeability and Core Loss Process Step Temperature Range Tunnel FurnaceExit Temperature 1800 to 2300 Degrees F. (or 1800 to 2150 Deg. F.) HotRolling Finish Temperature 1450 to 1800 Degrees F. (or 1500 to 1700 Deg.F.) Coiling Temperature 900 to 1500 Degrees F. (or 950 to 1450 Deg. F.)Batch Anneal Soak Temp (in lieu of Continuous Anneal) 1000 to 1900Degrees F. (or 2100 Deg F.), or 1000 to 1550 Deg. F. (or 1900 Deg F.),or 1450 Deg. F. to 2100 Deg F.. Continuous Anneal Temp (in lieu of BatchAnneal) 1400 to 2000 Degrees F. (or 2100 Deg F.), or 1550 to 1900 Deg.F. (or 2100 Deg F.) First Cold Rolling Temperature Ambient, or greater(May need > 100 F. for Si > 2.0%) Batch Anneal Soak Temp (in lieu ofContinuous Anneal) 1000 to 1900 Degrees F. (or 2100 Deg F.), or 1000 to1550 Deg. F. (or 1900 Deg F.), or 1450 Deg. F. to 2100 Deg F..Continuous Anneal Temp (in lieu of Batch Anneal) 1400 to 2000 Degrees F.(or 2100 Deg F.), or 1550 to 1900 Deg. F. (or 2100 Deg F.) Second ColdRolling Temperature Ambient, or greater (May need >100 F. for Si > 2.0%)Customer Anneal 1400 to 1800 F. (or 1400 to 1675 F.), or greater, for 45min. to 1 hour (or outside of this duration)

The multiple cold rolling steps with an intermediate annealing stepbetween the cold rolling steps allows for the desired magneticproperties for the thinner ranges of steel sheets (e.g., 0.005″ to0.018″, 0.02″ or the like), and particularly with respect to steelsheets with silicon levels greater than 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, orthe like. In one example, using a silicon steel of 3% and including anannealing step after hot rolling and before a first cold rolling step(e.g., one or more first cold rolling passes), an intermediate annealingstep after the first cold rolling step, a final (e.g., second) coldrolling step (e.g., one or second cold rolling passes) and no additionalintermediate annealing steps until stamping and customer annealing, asteel sheet with a thickness of approximately 0.015″ may be achieved(see Table 14). Other thicknesses described herein may also be achieved,as described in other examples presented below. The magnetic propertiesachieved using this particular type of routing, silicon content (e.g.,silicon content above 2.8%, such as 3% or other like silicon contentdescribed herein), and steel sheet thickness of less than 0.018″, mayinclude a core loss range of 0.80 w/lb to 1.6 w/lb (or to 1.8 w/lb) anda permeability range of 800 G/Oe to 2000 G/Oe (or to 2500 G/Oe) (e.g.,measured at 1.5 Tesla), or core loss or permeability ranges that fallwithin, overlap, or fall outside of these stated ranges. Table 14illustrates that using the higher silicon levels, thinner steelthicknesses (e.g., multiple cold rolling steps or the thin cast stripsteel described below), and higher customer annealing temperatures, thepresent invention can achieve similar core losses and betterpermeability than the steels with the same, similar, or lower siliconcontent that were produced using an annealing step after cold rolling(see Table 12 routings 1 and 2).

TABLE 14 Si Content vs. Thickness vs. Customer Annealing Temperature vs.Magnetic Properties Customer Annealing Si Content Thickness TemperatureCore Loss Permeability 3% 0.0178″ 1600 Deg F. 1.48 W/lb 2022 G/Oe 3%0.0152″ 1600 Deg F.  1.4 W/lb 1849 G/Oe 3% 0.0152 1700 Deg F. 1.38 W/lb1611 G/Oe

In another embodiment of the invention, instead of, or in addition to,utilizing multiple cold rolling steps to produce steels at the lower endof the range of the thickness of the steel sheets (e.g., fromapproximately 0.005″ to 0.015″, 0.018″, 0.02″, 0.031″, 0.035″, or thelike), the present invention may begin by utilizing thinner steel sheetsat the beginning of the process. For example as described above, thethicknesses of the steel sheets after hot rolling are typically 0.060″to 0.120,″ which are produced from steel slabs that typically havethicknesses that range between 1.5″ to 3″ (or slabs that fall within,overlap, or are outside of this range). In some embodiments of theinvention, instead of using steel slabs and hot rolling the steel slabsin one or more hot rolling passes to the desired thicknesses,continuously cast thin steel strips (e.g., thin strip cast steel) may beutilized in order to begin the process of the present invention with athinner steel sheet.

In one embodiment of the invention, as illustrated in FIG. 4, theprocess may begin with manufacturing or purchasing (e.g., from anothermanufacturer) thin strip cast steel, as illustrated by block 12. Thinstrip cast steel may be manufactured by a process that includes meltingscrap steel in an EAF and tapping the EAF so that the molten metal flowsinto a ladle. Ladle treatments may be performed, such as applyingcomponents for alloying the steel to the desired composition, achievingthe desired temperature for the molten metal, or the like. The ladle ispositioned over a tundish and the molten metal is transferred to thetundish. The tundish is drained into a water cooled mold that is used tosolidify the molten metal. In the mold a thin shell of metal issolidified near the walls of the mold while steel in the middle of themold remains molten. As the metal exits the mold the metal has a hardshell with a molten interior, at this point the metal is called astrand. The strand is then passed through multiple pairs of water-cooledrollers, which support and cool the strand as the molten metal withinthe interior of the strand solidifies. The strand may also pass througha cooling chamber that sprays cooling liquid, such as water, on thestrand to help further solidify the core of the strand. The strand maypass through various rolling operations to straighten, smooth, reducethe thickness, or the like of the strand and form a coil. In someembodiments of the invention the thin strip cast steel produced by thecontinuous casting process may have a thickness less than or equal to0.035″, 0.065″, 0.1 or other thickness described herein. In oneembodiment of the invention, the thickness of the thin strip cast steelmay have a thickness that is less than or equal to 0.04″ 0.05″, 0.06″,0.07″, 0.08″, 0.09″, 0.10″, 0.11″, 0.12″, 0.15, or 0.2″. In otherembodiments of the invention the ranges of the thicknesses of the thinstrip cast steel may be within, overlap, or fall outside of thesevalues.

The present invention may include utilizing the continuous castingprocess to produce, or otherwise purchase, steel coils with a thicknessless than 0.15″, 0.125″, 0.1″, 0.8″, 0.065″, or 0.04″ (or other likethickness whether or not specifically discussed herein). In the presentinvention, the process may utilize the thin strip cast steel in order toavoid the need for hot rolling a slab and performing multiple coldrolling steps to manufacture steel sheets with the desired thicknesses.In some embodiments of the invention since the thickness of thecontinuously cast steel sheet is less than 0.1″, 0.065″, or 0.04″ (orother like thickness discussed herein) the steel sheet is thin enough toroll into a thickness between 0.005″ to 0.015″, 0.018″, 0.02″, 0.031″,0.035″, or the like, in a single cold rolling pass. Therefore, in someembodiments of the present invention the process for manufacturing steelsheets with the desired magnetic properties would include procuring(e.g., manufacturing or obtaining) a continuously cast steel sheet witha thickness equal to or less than 0.1″ (or other thickness describedherein), as illustrated by block 12 of FIG. 4. As illustrated by block55, the thin strip cast steel sheet may be optionally pickled. Anannealing step (e.g., batch annealing or continuously annealing) isperformed on the cast steel sheet, as illustrated by block 60 of FIG. 4.For example, in one embodiment of the invention the annealing step is ahigh temperature annealing step, such as annealing at a temperature of1550 degrees F. (or within a range of 1000 to 2100 degrees F.). In oneembodiment of the invention, after annealing only a single cold rollingstep (e.g., with one or more cold rolling passes) is needed to producethe steel of the desired thickness between 0.005″ to 0.015″, 0.018″,0.020″, 0.031″, 0.035″, or the like, as illustrated by block 70. Inother embodiments of the invention, as previously discussed two or morecold rolling steps (e.g., each with one or more cold rolling passes) maybe utilized with or without intra-annealing steps between the multiplecold rolling steps and/or passes. However, regardless of the number ofcold rolling steps or passes there is no annealing step after the lastcold rolling step and before the optional tension leveling and coating,or optional roughing or temper rolling and tension leveling, asillustrated by blocks 75, 80, 90 of FIG. 4. Moreover, there is noannealing step after cold rolling and before stamping and annealing atthe customer, as illustrated by blocks, 100, 110, and 120 of FIG. 4.

The use of a thin strip cast steel product with a reduced thickness inthe present invention allows for the desired magnetic properties for thethinner ranges of steel sheets (e.g., 0.005″ to 0.010″, 0.015″, 0.018″,0.02″, 0.031″, or the like). The magnetic properties achieved using thisparticular type of routing may include a core loss range of 0.80 w/lb to1.25 w/lb (or to 1.6 w/lb, 1.8 w/lb, or more) and a permeability rangeof 800 G/Oe to 1500 G/Oe (or to 2500 G/Oe) (e.g., measured at 1.5Tesla), or core loss or permeability ranges that fall within, overlap,or fall outside of these stated ranges, as discussed throughout thisspecification.

In one example embodiment of the invention two rolled samples of theelectrical steel discussed herein were produced for high frequencyapplications, in which steel was produced having a composition of 2.90%wt Si; 0.62% wt Al; and 0.28% Mn. In some embodiments, in order toachieve the desired properties at the thinner steel thicknesses thecomposition of particular elements previously described herein arecontrolled to tighter ranges, as illustrated in Table 15.

TABLE 15 Range of Elements for Desired Electrical Steel Permeability andCore Loss Properties at Thicknesses less than 0.015 inches SpecificComposition Composition of Samples Element (by weight percent) (byweight percent) Silicon (Si) 2.8-3.5%  2.9% Aluminum (Al)  0.5-0.75%0.62% Manganese (Mn) 0.2-0.4% 0.28%

The steel in the example embodiment was produced by hot rolling a 2-inchslab down to a steel sheet with a thickness of 0.073 inches in multiplehot rolling passes (e.g., in 6 hot-rolling passes). Thereafter, thesteel sheet with the 0.073 inch thickness after hot rolling was pickledto remove scale from the steel sheet surface. After pickling, the steelsheet was coiled and batch annealed at a temperature of 1700 degrees F.After batch annealing the steel sheet was cold rolled to a post firstcold rolled thickness of 0.036 inches in one or more cold rolling steps(e.g., one cold rolling pass). Thereafter, the steel sheet with a 0.036inch post first cold roll thickness was batch annealed again at atemperature of 1550 degrees F.

The steel sheet was then split into two separate steel rolls, one ofwhich was cold rolled to a post second (or final) cold rolled thicknessof 0.0118 inches in one or more cold rolling passes (e.g., 6 passes),while the other roll was rolled to a post second (or final) cold rolledthickness of 0.008 inches in one or more cold rolling passes (e.g.,greater than 6 cold rolling passes). At these thicknesses, the steelsheets may need a very smooth surface to achieve the desired electricaland mechanical properties in the final applications (e.g., aftercustomer stamping and final customer annealing), as such, the steels maybe produced with a surface roughness that is less than 15, 14, 13, 12,11, 10, 9, 8, 7, 6, or 5 microns, or the like. The samples producedherein had an average surface roughness of 6 microns. The steel coilswere tension leveled after the second (or final) cold rolling step inorder to flatten the edges of the steel sheets. In some embodiment, itis at this point that the steel coils may be coated, however, theexamples produced herein were not coated. At this point in the processthe steel coils would be sent to the customer without an annealing stepafter the second (or final) cold rolling step, for the customer stampingstep and customer final annealing step after stamping in order to createthe desired products. To simulate this process samples were taken fromthe steel coils and annealed. With respect to the steel samples having athickness of 0.0118 inches the samples were annealed at 1550 degrees F.at 55 F dewpoint in a Hydrogen/Nitrogen (HNx) atmosphere. The steelsamples having a thickness of 0.008 inches were annealed at 1600 degreesF. at 55 dewpoint in the HNx atmosphere. The samples were then testedover various frequencies as illustrated below in Table 16. We note thatthe samples discussed in Tables 16-18 are illustrated as having a coreloss measured using the units of w/kg instead of the w/lbs previouslydiscussed herein. The unit changes is used in order to compare thesamples made in the present invention with products that are on themarket that utilize the traditional process that includes an annealingstep after final cold rolling (e.g., using a continuous annealing line)and before the products are shipped to the customer for stamping andfinal customer annealing. However, we again, further note that the coreloss and permeability values discussed herein, are the values that wouldbe achieved after the final customer annealing.

TABLE 16 Core Loss and Permeability of 0.0118 and 0.008 Steel SheetThicknesses Measured at the Head (H) and Tail (T) of the Coil Location HT H T H T H T H T H T H T 50 Hz 50 Hz 60 Hz 60 Hz 200 Hz 200 Hz 400 Hz400 Hz 600 Hz 600 Hz 800 Hz 800 Hz 1000 1000 Thick- @ @ @ @ @ @ @ @ @ @@ @ Hz @ Hz @ ness Units 1.5 T 1.5 T 1.5 T 1.5 T 1.0 T 1.0T 1.0 T 1.0 T1.0 T 1.0 T 1.0 T 1.0 T 1.0 T 1.0 T .0116″ w/kg 2.31 2.31 2.87 2.86 5.7815.4 15.32 28.73 27.5 44.44 42.75 65.04 64.33 G/Oe 1610 1744 1603 17459861 7986 8137 6347 6712 5391 5676 4626 4683 .008″ w/kg 2.51 3.06 5.512.30 12.01 45.45 44.28 G/Oe 1578 1570 8844 9054 9674 6919 7181 B50Tesla 1.69 1.69

The samples described with respect to Table 16 were compared againstsimilar products on the market that were made utilizing an annealingstep after the final cold rolling process and utilizing a continuousannealing process instead of batch annealing. Table 17 illustrates thecomparisons of products on the market that utilize annealing after finalcold rolling before stamping and customer annealing at various testpoints and the samples of the present invention for steels ofapproximately 0.0118 inches. Table 18 illustrates the comparisons ofproducts on the market that utilize annealing after final cold rollingbefore stamping and customer annealing at various test points and thesamples of the present invention for steels of approximately 0.008inches.

TABLE 17 Comparison of 0.0118 inch Steels of the Present Invention withProducts on the Market that Utilize Annealing after the Final ColdRolling Step Products With 0.0118 Thickness Annealing after Products ofthe Present Invention Comparison Product Test Final Cold Rolling presentinvention Improvement 1 (0.0118 inch 1.0 T w/kg @ 400 Hz 16.0 15.35Improvement thickness) B50 Perm 1.62 1.69 Improvement 2 (0.0118 inch 1.0T w/kg @ 400 Hz 14.5 15.35 thickness) B50 Perm 1.66 1.69 Improvement 3(0.0118 inch 1.0 T w/kg @ 400 Hz 15.0 15.35 thickness) B50 Perm 1.601.69 Improvement 4 (0.0118 inch 1.0 T w/kg @ 400 Hz 15.0 15.35thickness) 5 (0.0118 inch 1.0 T w/kg @ 400 Hz 15.0 15.35 thickness) B50Perm 1.60 1.69 Improvement 6 (0.0118 inch 1.0 T w/kg @ 400 Hz 16.0 15.35Improvement thickness) B50 Perm 1.64 1.69 Improvement

TABLE 18 Comparison of 0.008 inch Steels of the Present Invention withProducts on the Market that Utilize Annealing after the Final ColdRolling Step Products With 0.008 Thickness Annealing after Products ofthe Present Invention Comparison Product Test Final Cold Rolling presentinvention Improvement 1 (0.007 inch 0.9 T w/kg @ 400 Hz 13.2 10.2Improvement thickness) 1.0 T Perm 5982 9814 Improvement 2 (0.010 inch1.0 T w/kg @ 400 Hz 12.8 12.5 Improvement thickness) B50 Perm 1.63 1.69Improvement 3 (0.008 inch 1.0 T w/kg @ 400 Hz 11.9 12.5 thickness) B50Perm 1.64 1.69 Improvement 4 (0.008 inch 1.0 T w/kg @ 400 Hz 12.7 12.5Improvement thickness) B50 Perm 1.67 1.69 Improvement 5 (0.008 inch 1.0T w/kg @ 400 Hz 12.2 12.5 thickness) 1.0 T Perm 8035 9814 Improvement 6(0.008 inch 1.0 T w/kg @ 400 Hz 12.9 12.5 Improvement thickness) 1.0 TPerm 7955 9814 Improvement

Based on a number of factors, including but not limited to the siliconcontent of the steel, the thickness of the steel sheet, the annealingtemperatures, and the process of performing an annealing step betweenhot rolling and before cold rolling and forgoing an annealing step afterthe last cold rolling pass before the sheet is sent to the customer forfurther processing, the core losses and permeability may fall within anumber of different ranges for steels of the present invention whichhave thicknesses that are less than 0.02, 0.018, 0.015, 0.012, 0.01,0.008, or the like. In some embodiments of the invention the core lossmeasured at 1.0 T at 400 Hz may be below 20.0, 19.0, 18.0, 17.0, 16.0,15.5, 15.0, 14.5, 14.0, 13.5, 13.0, 12.5, 12.0, 11.5, 11.0, 10.5, 10.0,or the like w/kg, may be within, overlapping, or outside of any rangesbetween these core loss values or other core loss values notspecifically recited. In addition to these core loss values, thepermeability measured at 1.0 T at 400 Hz may be greater than 4000, 4500,5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, or 9500 G/Oe, maybe within, overlapping, or outside of any ranges between thesepermeability values or other permeability values not specificallyrecited. In addition to the permeability measured at 1.0 T at 400 Hz,the B50 Perm measurement may be greater than 1.55, 1.56, 1.57, 1.58,1.59, 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69, 1.70,1.71, 1.72, 1.73, 1.74, 1.75, or the like Tesla, may be within,overlapping, or outside of any ranges between these B50 measurementvalues or other values not specifically recited.

Another feature of the electrical steel of the present invention is thatin addition to the improved core loss and permeability properties, theelectrical steel has improved mechanical properties. Table 19 belowillustrates the improved mechanical properties both before and aftercustomer annealing of the steel of the present invention (e.g., steelmanufactured from a process that includes an annealing step between hotrolling and cold rolling, and after customer stamping, but not betweenthe last cold rolling step and the customer annealing step). Asillustrated in Table 19, before the customer annealing step the yieldstrength and the ultimate tensile strength of the electrical steels madefrom the new process of the present invention are almost twice as highas the electrical steels made from the traditional process. Moreover,after the customer annealing step the mechanical properties of theelectrical steels made from the new process are similar to, or are animprovement over, the mechanical properties of the electrical steelsmade from the traditional process.

Table 19 also illustrates that the hardness of the electrical steelsmade from the new process are higher than the electrical steels madefrom the traditional process both before and after customer annealing.In addition, Table 19 illustrates the elongation percent (El %) valuefor the steels, which is a measurement of the ductility of the steel. Insome embodiments of the invention, lower El percentages may be desiredbecause it may be easier to stamp parts from steels with lower Elpercentages.

TABLE 19 Mechanical Properties of Electrical Steels of the New Processvs. Traditional Process Before Customer Anneal After Customer AnnealSteel Product YS UTS EI Hardness YS UTS EI Hardness Routing Type (Si wt%) (ksi) (ksi) (%) (Rb) (ksi) (ksi) (%) (Rb) Traditional Si 0.25% 56.662.3 20.8 68 16.9 43.4 32.7 58 Traditional Si 0.4% 56.9 66.9 33.3 7021.0 45.9 33.3 46 Traditional Si 1.05% 61.0 72.3 15.1 73 29.1 51.9 30.869 New Si 1.05% 129.4 130.1 1.1 98 35.6 58.6 24.2 71 Traditional Si1.35% 66.1 75.5 13.5 70 33.5 53.6 26.6 64 Traditional Si 2.2% 72.9 87.414.4 80 47.3 58.1 16.2 68 New Si 2.2% 138.1 141.7 1.1 99 46.1 64.3 17.875

Table 19 illustrates a single test result for particular types of steel.It should be understood that the mechanical properties achieved in thepresent invention may fall within various ranges. For example, theSilicon 1.05 wt % steel may have the following property ranges beforecustomer annealing: YS—100 to 160 ksi; UTS—100 to 160 ksi; EI of 0.5 to2; and Hardness of 90 to 110; and after customer annealing: YS—25 to 45ksi; UTS—40 to 80 ksi; EI of 15 to 35; and Hardness of 60 to 80. Inanother example, the Silicon 2.2 wt % steel may have the followingproperty ranges before customer annealing: YS—110 to 170 ksi; UTS—110 to170 ksi; EI of 0.5 to 2; and Hardness of 90 to 110; and after customerannealing: YS—35 to 55 ksi; UTS—45 to 85 ksi; EI of 10 to 25; andHardness of 65 to 85. In other embodiments of the invention the rangesmay fall within, overlap, or fall outside of these stated ranges.

For steels with higher silicon levels (e.g., above 2.2% Si) themechanical properties of steels manufactured using the new process mayalso be improved over the mechanical properties of steels manufacturedusing the traditional process. For example, for steels with siliconcontents of 2.6%, 3.0%, or more, the hardness of the steels may begreater than 80, 85, 90, 95, or 100 Rb. Moreover, the mechanicalproperties of YS, UTS, and El may be greater than the values (or ranges)described with respect to Table 19.

The electrical steels of the present invention described herein may beutilized for various electric motor applications. For example, theelectrical steels from the present invention may be utilized forapplications in which higher strength electrical steels are needed,applications in which higher frequencies are required, or the like.

In some applications electric motors have a stationary stator that haswindings or permanent magnets that surround a core comprising layers ofelectrical steel sheets. The rotor is located within the stator and hasconductors that carry currents that interact with the magnetic field ofthe stator for driving a shaft attached to the rotor. In otherapplications electric motors may have rotors that are coupled to thepermanent magnets instead of the stator, while the stator includes theconductors. The electrical steels of the present invention can be usedin both applications, but in one embodiment of the invention theelectrical steels may be particularly useful in electric motors in whichthe rotor has the permanent magnets and the stator has the conductors.In this embodiment, electrical steels made from the traditional processdescribed herein (e.g., having an annealing step after cold rolling andbefore customer stamping and annealing) may be used to create the statorportion of the electrical steel, but not the rotor portion. For example,when permanent magnets are used on the rotor itself, the rotor is notmagnetized because the magnets create the magnetic field. As such, inthese applications the polarity of the stator is changed to rotate therotor within the stator. In order to improve the efficiency of the motorfor rotating at higher levels of rotations per minute (RPM) and higherlevels of torque, the rotor strength has to be improved. As such, highstrength steel can be used for the rotor to result in higher levels ofRPM and torque for the electric motor. When customers use electricalsteels made from the traditional process described herein, theelectrical steel sheets are annealing after cold rolling, then theelectrical steel is shipped to the customer for stamping and customerannealing to achieve the desired magnetic properties. The stator androtor parts are stamped out of the electrical steel sheets in a singlestamping process. However, the rotor parts made from the electricalsteels produced from the traditional process do not have the requiredstrength to meet the desired motor applications which require higherlevels of RPMs and torque. As such, the rotor parts cannot be used andare scraped or used for other applications. Instead, the rotor parts aremade from steel products that have higher strengths and the permanentmagnets are coupled to the rotors made from the higher strengthmaterial. Alternatively, the stamped stator parts are customer annealedto achieve the desired magnetic properties. This situation creates wastewithin the manufacturing process and increases the costs of the electricmotors (e.g., additional stamping process costs, additional highstrength steel material costs, and the like).

Alternatively, the electrical steels of the present invention (e.g.,which do not include an annealing step after cold rolling and beforecustomer stamping and customer annealing) have a higher strength beforestamping and customer annealing (see Table 19). As such, the electricalsteels of the present invention may be stamped by the customer to createthe rotor and stator parts. The stator parts may then be annealed by thecustomer to achieve the desired magnetic properties, while the rotorparts stamped from the same electrical steel sheet may be utilizedwithout the customer annealing step or annealed at a lower customerannealing temperature to preserve the higher strength of the steel (seeTable 19). By annealing at lower customer annealing temperatures therotor parts may retain some of the mechanical properties (e.g., betterthan the stator) while the core loss and permeability would still beimproved (e.g., not as good as the stator), but the costs could bereduced due to increased productivity and the lower annealingtemperature (e.g., don't have to anneal as long and can save electricitythat is usually required to reach higher temperature annealing). Thepresent invention allows the customer to stamp the stator and rotorparts from the same sheet of metal without having to replace the stampedrotor parts with parts stamped from higher strength steels. In thetraditional process by annealing the electrical steel sheet after thefinal cold rolling step and before shipping to the customer for stampingand final annealing the desired magnetic properties may be achieved, butthe strength of the electrical steel sheet is sacrificed.

Another application of the electrical steels of the present inventionmay include applications (e.g., motors, or the like) that require higheroperating frequencies. For example, some electric motors may onlyrequire frequencies of around 60 Hz (e.g., the alternating currentswitches from + to − at a rate of 60 times per second), or other likefrequencies. However, other electric motors, such as electric motorsused in cars may be required to operate at approximately 400 Hz, 500 Hz,600 Hz, 700 Hz, 800 Hz, 900 Hz, 1000 Hz, or higher (or any ranges thatfall within, overlap, or are outside of these ranges). For example, insome applications steels with silicon values greater than 2.2 wt % andwith thicknesses less than or equal to 0.02 inches (or less than orequal to 0.014″) may be particularly useful in motor applications withhigh frequencies. In order to achieve the desired properties at thesehigher frequency levels the size of the grains in the electrical steelsheets are kept to smaller grain sizes. When a cycle occurs within theelectrical steel, the domains of the grain flip back and forth betweentwo different orientations. As such, the domains of the grains arealigned in a first direction and are flipped into a second direction andback to the first direction for each cycle. The larger the grain sizethe larger the domain of the grain, which requires more energy to reachthe higher frequencies because of the larger area that has to be coveredin a shorter amount of time. At lower frequencies, larger grain sizesare not an issue because the amount of energy needed to flip the domainis not restrictive. However, at higher frequencies (e.g., 400 Hertz ormore as described above) it is harder to flip the domain fast enough toreach frequencies of 400 Hz or higher, and as such, it takes more energyto flip the domain when the size of the grains are larger. Theadditional energy required to achieve the higher frequency levelsincreases the heat loss and reduces the efficiency of the electricmotor. As such, smaller grain sizes are more efficient at higherfrequencies. The process of the present invention can produce electricalsteels with smaller grain sizes than the grain sizes of the electricalsteels produced by the traditional process (as described above). Inaddition to the smaller gain sizes, the present invention still achievesthe same, similar, or improved magnetic properties (e.g., core loss,permeability, or the like) and mechanical properties as can be achievedusing the traditional process (as described above).

It should be understood that when discussing the magnetic properties ofthe electrical steel, the magnetic properties of the electrical steelare based on the composition of the electrical steel, the processing ofthe semi-processed electrical steel sheet, and the customer stamping andfinal customer anneal occurring at the customer. The final magneticproperties of the steel are provided after processing at the customer,and may or may not be dependent on the shape of the stamped part madefrom the electrical sheet steel sent to the customer.

Moreover, it should be understood that the lower limit of any of thecomponents discussed herein may be 0.0005, 0.001, 0.005, 0.01, or thelike.

While certain exemplary embodiments have been described herein, andshown in the accompanying drawings, it is to be understood that suchembodiments are merely illustrative of and not restrictive on the broadinvention, and that this invention not be limited to the specificconstructions and arrangements shown and described, since various otherchanges, combinations, omissions, modifications and substitutions, inaddition to those set forth in the above paragraphs, are possible. Thoseskilled in the art will appreciate that various adaptations andmodifications of the just described embodiments can be configuredwithout departing from the scope and spirit of the invention. Therefore,it is to be understood that, within the scope of the appended claims,the invention may be practiced other than as specifically describedherein.

What is claimed is:
 1. A stamped part formed from a motor lam electricalsteel, comprising: the motor lam electrical steel comprising: silicon(Si) in a range of 2.2-3.5% weight; aluminum (Al) in a range of 0.15-1%weight; manganese (Mn) in a range of 0.005-1% weight; carbon (C) lessthan or equal to 0.04% weight; and antimony (Sb) or Tin (Sn) less thanor equal to 0.1% weight; wherein a remainder comprises unavoidableimpurities and iron; wherein the motor lam electrical steel is producedby: hot rolling steel in one or more hot rolling passes into a steelsheet to a post hot rolling thickness of less than 0.1 inches; annealingthe steel sheet in a first anneal after hot rolling, wherein theannealing after the hot rolling is a post hot rolling batch anneal, andwherein the annealing after the hot rolling is performed at a post hotrolling annealing temperature that is greater than or equal to 1550degrees Fahrenheit; cold rolling the steel sheet in one or more firstcold rolling passes after the first anneal to a post first cold rollingthickness less than 0.05 inches; annealing the steel sheet in a secondanneal after the one or more first cold rolling passes, wherein theannealing in the second anneal after the one or more first cold rollingpasses is a post first cold rolling batch anneal, and wherein theannealing in the second anneal after the one or more first cold rollingpasses is performed at a post first cold rolling annealing temperaturethat is greater than or equal to 1550 degrees Fahrenheit; cold rollingthe steel sheet in one or more final cold rolling passes after thesecond anneal to a post cold rolling thickness of less than 0.015 inchesto form the motor lam electrical steel; and wherein the motor lamelectrical steel is stamped into the stamped part and thereafter finalannealed without an intermediate anneal after the one or more final coldrolling passes, and before the stamping and the final annealing, andwherein the final annealing after stamping is performed at a poststamping annealing temperature that is greater than or equal to 1550degrees Fahrenheit; and wherein the stamped part has a permeabilitygreater than or equal to 4500 G/Oe and a core loss less than or equal to70 W/kg when tested at 1.0 T at 1000 Hz after the annealing after thestamping in all directions in the stamped part.
 2. The stamped partformed from the motor lam electrical steel of claim 1, wherein thestamped part has a surface roughness less than or equal to 15 microns.3. The stamped part formed from the motor lam electrical steel of claim1, wherein the motor lam electrical steel comprises: silicon (Si) is inthe range of 2.8-3.5% weight; manganese (Mn) in the range of 0.2-0.4%weight; and aluminum (Al) in the range of 0.5-0.75% weight.
 4. Thestamped part formed from the motor lam electrical steel of claim 1,wherein the motor lam electrical steel is further produced by sendingthe motor lam electrical steel to a customer for the stamping into thestamped part and the final annealing after the stamping.
 5. The stampedpart formed from the motor lam electrical steel of claim 1, wherein thepost hot rolling annealing temperature is greater than or equal to 1600degrees F., and the post first cold rolling annealing temperature isgreater than or equal to 1600 degrees F.
 6. The stamped part formed fromthe motor lam electrical steel of claim 1, wherein the permeability isgreater than or equal to 6000 G/Oe and the core loss is less than orequal to 20.0 W/kg when tested at 1.0 T at 400 Hz after the annealingafter the stamping in all directions of the stamped part.
 7. The stampedpart formed from the motor lam electrical steel of claim 6, wherein thepermeability is greater than or equal to 7500 G/Oe and the core loss isless than or equal to 16.0 W/kg when tested at 1.0 T at 400 Hz after theannealing after the stamping in all directions of the stamped part.
 8. Astamped part formed from a motor lam electrical steel, comprising: themotor lam electrical steel comprising: silicon (Si) in a range of2.2-3.5% weight; aluminum (Al) in a range of 0.15-1% weight; manganese(Mn) in a range of 0.005-1% weight; carbon (C) less than or equal to0.04% weight; and antimony (Sb) or Tin (Sn) less than or equal to 0.1%weight; wherein a remainder comprises unavoidable impurities and iron;wherein the motor lam electrical steel is produced by: procuring asteel, wherein a thickness of the steel is less than or equal to 0.1inches; annealing the steel, wherein the annealing is a batch annealing,and wherein the annealing is performed at an annealing temperature thatis greater than or equal to 1550 degrees Fahrenheit; cold rolling thesteel in one or more cold rolling passes after the annealing into asteel sheet with a post cold rolling thickness less than 0.015 inches toform the motor lam electrical steel; wherein the motor lam electricalsteel is stamped into the stamped part and thereafter final annealedwithout an intermediate anneal after the one or more cold rollingpasses, and before the stamping and the final annealing, and wherein thefinal annealing after the stamping is performed at a post stampingannealing temperature that is greater than or equal to 1550 degreesFahrenheit; and wherein the stamped part has a permeability greater thanor equal to 4500 G/Oe and a core loss less than or equal to 70 W/kg whentested at 1.0 T at 1000 Hz after the annealing after the stamping in alldirections in the stamped part.
 9. The stamped part formed from themotor lam electrical steel of claim 8, wherein the stamped part has asurface roughness less than or equal to 15 microns.
 10. The stamped partformed from the motor lam electrical steel of claim 8, wherein theelectrical steel comprises: silicon (Si) is in the range of 2.8-3.5%weight; manganese (Mn) in the range of 0.2-0.4% weight; and aluminum(Al) in the range of 0.5-0.75% weight.
 11. The stamped part formed fromthe motor lam electrical steel of claim 8, wherein the motor lamelectrical steel is further produced by sending the steel sheet to acustomer for the stamping and the final annealing after the stamping.12. The stamped part formed from the motor lam electrical steel of claim8, wherein the annealing temperature is greater than or equal to 1600degrees F., and the post stamping annealing temperature is greater thanor equal to 1600 degrees F.
 13. The stamped part formed from the motorlam electrical steel of claim 8, wherein the permeability is greaterthan or equal to 6000 G/Oe and the core loss is less than or equal to20.0 W/kg when tested at 1.0 T at 400 Hz after the annealing after thestamping in all directions in the stamped part.
 14. The stamped partformed from the motor lam electrical steel of claim 13, wherein thepermeability is greater than or equal to 7500 G/Oe and the core loss isless than or equal to 16.0 W/kg when tested at 1.0 T at 400 Hz after theannealing after the stamping in all directions of the stamped part. 15.A method of manufacturing a stamped part formed from a motor lamelectrical steel, comprising: hot rolling steel into a steel sheet inone or more hot rolling passes to a post hot rolling thickness of lessthan 0.1 inches; annealing the steel sheet in a first anneal after hotrolling, wherein the annealing after the hot rolling is a post hotrolling batch annealing, and wherein the annealing after the hot rollingis performed at a post hot rolling annealing temperature that is greaterthan or equal to 1550 degrees Fahrenheit; cold rolling the steel sheetin one or more first cold rolling passes after the first anneal to apost first cold rolling thickness less than 0.05 inches; annealing thesteel sheet in a second anneal after the one or more first cold rollingpasses, wherein the annealing in the second anneal after the one or morefirst cold rolling passes is a post first cold rolling batch annealing,and wherein the annealing in the second anneal after the one or morefirst cold rolling passes is performed at a post first cold rollingannealing temperature that is greater than or equal to 1550 degreesFahrenheit; cold rolling the steel sheet in one or more final coldrolling passes after the second anneal to a post cold rolling thicknessof less than 0.015 inches to form the motor lam electrical steel;wherein the motor lam electrical steel is stamped into the stamped partand thereafter final annealed without an intermediate annealing afterthe one or more final cold rolling passes, and before the stamping andthe final annealing, and wherein the final annealing after stamping isperformed at a post stamping annealing temperature that is greater thanor equal to 1550 degrees Fahrenheit; wherein the motor lam electricalsteel comprises: silicon (Si) in a range of 2.2-3.5% weight; aluminum(Al) in a range of 0.15-1% weight; manganese (Mn) in a range of 0.005-1%weight; carbon (C) less than or equal to 0.04% weight; and antimony (Sb)or Tin (Sn) less than or equal to 0.1% weight; wherein a remaindercomprises unavoidable impurities and iron; wherein the stamped part haspermeability greater than or equal to 4500 G/Oe and a core loss lessthan or equal to 70 W/kg when tested at 1.0 T at 1000 Hz after theannealing after the stamping in all directions in the stamped part. 16.The method of claim 15, wherein the motor lam electrical steelcomprises: silicon (Si) is in the range of 2.8-3.5% weight; manganese(Mn) in the range of 0.2-0.4% weight; and aluminum (Al) in the range of0.5-0.75% weight.
 17. The method of claim 15, wherein the post hotrolling annealing temperature is greater than or equal to 1600 degreesF., and the post first cold rolling annealing temperature is greaterthan or equal to 1600 degrees F.
 18. The method of claim 15, wherein thepermeability is greater than or equal to 6000 G/Oe and the core loss isless than or equal to 20.0 W/kg when tested at 1.0 T at 400 Hz after theannealing after the stamping in all directions in the stamped part afterthe annealing after the stamping in all directions of the stamped part.19. The method of claim 15, wherein the permeability is greater than orequal to 7500 G/Oe and the core loss is less than or equal to 16.0 W/kgwhen tested at 1.0 T at 400 Hz after the annealing after the stamping inall directions of the stamped part.
 20. A method of manufacturing astamped part formed from a motor lam electrical steel, comprising:procuring a steel, wherein a thickness of the steel is less than orequal to 0.1 inches; annealing the steel, wherein the annealing is abatch annealing, and wherein the annealing is performed at an annealingtemperature that is greater than or equal to 1550 degrees Fahrenheit;cold rolling the steel sheet in one or more cold rolling passes afterthe annealing to a post cold rolling thickness of less than 0.015 inchesto form a motor lam electrical steel; and wherein the motor lamelectrical steel is stamped into the stamped part and thereafter finalannealed without an intermediate annealing after the one or more coldrolling passes, and before the stamping and the final annealing, andwherein the final annealing after the stamping is performed at a poststamping annealing temperature that is greater than or equal to 1550degrees Fahrenheit; wherein the motor lam electrical steel comprises:silicon (Si) in a range of 2.2-3.5% weight; aluminum (Al) in a range of0.15-1% weight; manganese (Mn) in a range of 0.005-1% weight; carbon (C)less than or equal to 0.04% weight; and antimony (Sb) or Tin (Sn) lessthan or equal to 0.1% weight; wherein the remainder comprisesunavoidable impurities and iron; wherein the stamped part haspermeability greater than or equal to 4500 G/Oe and a core loss lessthan or equal to 70 W/kg when tested at 1.0 T at 1000 Hz after theannealing after the stamping in all directions in the stamped part.